Gun perforator



Dec.

Il, ll\

R. R. THOMPSON ET AL 2,257,527

GUN PERFoRAToR Filed oct. 1.9, 1940 INV ENT ORS Patented Dec. 23, i941 YPTE r FFICE GUN PERFORATOR Ware Application October 19, 1940, vSerial No. 361,834

(ci. 16a-0.5)

4 Claims.

The present invention is directed to a gun perforator for use in bore holes and has particular reference to a firing chamber therefor.

As is known, the guns which are used for perforating casing in bore holes comprise an elongated gun body having spaced wells to accomf modate firing chambers, these chambers being removable metal cylinders having a central passage to receive a bullet and a charge of powder, and having means embedded in the charge of powder for firing it. The tiring circuit is ordinarily connected to the ring lament throughthe rear end of the ring chamber and this necessitates some sort of a conductor arranged in a passage connecting the rear end of the firing chamber to the exterior of the metal oody. When the charge explodes, the pressure exerted must be supported by the rear end of the ring chamber, and this leads to considerable iiculties in the matter of insulation. As will Je apparent, the conductor for the firing current must be insulated from the metal body in which it is arranged and this insulating mate- `ial is usually destroyed by the explosion.

The principal object of the present invention s the provision of a firing chamber for a gun )erforator so constructed that, up until the time 'he charge of powder is red, the conductor carlied in the firing current is insulated from the netal body containing the iiring chamber but, lpon the explosion, is brought into metal-tonetal contact with said metal nbody, thereby orming an eiective pressure resistant seal .gainst the pressure of the explosion. This peroits the use of insulation for long periods of ime and constitutes a considerable saving in the peration of the gun.

Further objects and advantages of the presen ovention will appear from the accompanying rawing in which:

Fig. 1 is a vertical section through a firing hamber constituting one embodiment of the resent invention; and

Fig. 2 is a similar view of another embodiient of the present invention.

Referring to Fig. 1 in detail, numeral l desigates a cylindrical metal insert adapted to be rranged in a well in a gunjbody and having a antral cavity 2 for accommodating a powder barge 3 and a bullet 4. The inner end of the avity 2 is connected to the exterior of body I y a passage 5, between which and the cavity roper is a .conical portion 6 forming a seat for conical valve 'l carrying a stem 8 extending irough the passage 5 to the exterior of the body rials have suicient resiliency to be compressed 'by the f orce of the explosion and to return to their normal shape after the explosion.

The insulated ringr Il is made of suflicient thickness to hold the conical valve 'i spaced from its seat 6, while the stem 8 is of such diameter as to be spaced from the wall of passage 5; The

stem is held in spaced relation to the wall of passage 5 by suitable packing 20 which also serves to hold out drilling uid.

Removably arranged in the recess 2 is a ring element comprising a cotter pin l2 having its prongs adapted to rest upon the top of the valve l and carrying three disks. The two outer disks I 3 are made of insulating material, while the middle disk I is made of metal, has its center cut away so as not to contact the cotter pin, and has its outer eceaupturned so as to press resiliently against the wally-of the cavity 2. The outer edge of disk l is preferably serrated or notched so as to form springuingers on its outer edge. The ring filament l5 is connected to the loop of the cotter pin and to the disk It.

The parts are shown in Fig. 1 in the position .they assume before the charge of powder-is exploded. When the charge explodes thev pressure exerted on the valve 1 compresses the insulating ring H and sets the valve on its seat 6 forming a metal-to-metal seal. When the pressure is released by projection of a bullet, the ring Il expands to its normal shape and raises valve l oli its seat.

The embodiment shown in Fig. 2 differs from that shown in Fig. 1 in that compression of the insulating material is not relied upon. In this figure parts corresponding to those shown in Fig. 1 bear the same numerals. Instead of valve 'I carrying a ange l0, the valve is connected'by a rivet or pin I1 to a. thin steel disk I8 which acts as a diaphragm and which rests ,on the insulating ring AI l. In this case, when the charge explodes the diaphragm I8 yields suiciently to permit the valve 'I to seat. l

It will be apparent that the above described embodiments are not intended to dene the scope of the present invention, but only to illustrate the nature thereof. Other modifications will occur to those skilled in the art Without departing from the basic principle of the present invention,

which is the provisionV of a conducting element for leading current into the tiring chamber which is normally held in spaced relation to the walls of the ring chamber and, therefore, insulated therefrom by a yieldable member which, upon the occurrence of an explosion, will permit the conductor to form a metal-to-metal seal with the Wall of the firing chamber.

The nature and objects of the present invention having been thus described and illustrated, what is claimed as new and useful and is desired to be secured by Letters Patent is:

1. A gun barrel for a bore hole gun comprising a metal body having an elongated recess adapted to receive a powder charge, a ring filament and a projectile and a smaller passage connecting to the inner end of said recess adapted to carry a conductor, a conductive metal element extending through said passage inspaced relation thereto and adapted to seat on the inner end of said l passage in metal-to-metal contact therewith, and

yieldable means associated with said element and adapted normally to hold it off its seat, to yield under explosion pressure to permit the seating of said element and to force said element oi its seat i after the explosion pressure subsides.

2. A gun barrel for a bore hole gun comprising a metal body having an elongated recess adapted to receive a powder charge, a :tiring filament and a projectile and a 'smaller passage connecting to the inner end of said recess adapted to carry a conductor, a metal stem physically independent of said firing filament extending through said passage in spaced relation to the wall thereof,

an enlarged head on the inner end of said stem` 4. A device according to claim 2 in which the yieldable means is a resilient disk supported in the recess on insulating material and physically connected on one side to the enlarged head and electrically connected on the other side to the iiring filament. l

ROBERT R. THOMPSON. WHITMAN D. MOUNCE. 

